1. Field of the Invention
This invention relates to data input technology, and more particularly, to a Chinese-character input method and system that allows users to input Chinese characters to a data processor with a reduced keyboard, such as a mobile-phone handset with a CCITT-compliant (Consultative Committee in International Telegraphy and Telephony) keyboard having only 12 keys. This invention allows the user to input Chinese characters to the data processor through a plurality of virtual keyboards which collectively display a set of phonetic symbols, such as those in the Mandarin Phonetic Symbol Set or the Roman Symbol Set, so that the user can perform the task of Chinese-character input through a pronunciation-based input scheme.
2. Description of Related Art
In this information age, electronic communication means, such as mobile phone and E-mail, have been replacing conventional mails for people to communicate with each other. The mobile phone, as a handy and convenient communication tool, is particularly rapidly expanding in the consumer market due to great demand from all walks of life. In Chinese-speaking areas, such as Taiwan, the sales in the past one year has exceeded the total of the past few years.
Conventional mobile-phone handsets only allow the user to perform speech communication. Newer models, in addition, allow the user to send E-mails and messages to the receiver. Since E-mail typically contains text, it is required to use the keyboard on the mobile-phone handset for text input. However, since a conventional mobile-phone handset is typically provided with a CCITT-compliant keyboard having 12 keys only, the text-input task is always laborious.
FIG. 1 is a front view of a conventional mobile-phone handset (designated by the reference numeral 100) that utilizes a CCITT-compliant keyboard (designated by the reference numeral 110). The mobile-phone handset 100 further includes a pair of control keys (SOFT) 121, 122; a shift key 123; and a 168.times.98 LCD (liquid crystal display) 130. The functions of the control keys 121, 122 and shift key 123 are well-known and not within the spirit and scope of the invention, so detailed description thereof will not be given in this specification. The CCITT-compliant keyboard 110 includes 12 keys: {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, {character pullout}, and {character pullout}. The user can use these keys to input both numbers and English letters to the mobile-phone handset 100, 10 which can then transmit the input message through radio link to the receiving side. When a specific key on the CCITT-compliant keyboard 110 is pressed, the number and letters printed on that key will be activated in a cyclic manner.
When the user wants to input a certain number, he/she needs just to press the key that prints the intended number. For instance, when the user wants to input the number "3" to the mobile-phone handset 100, he/she needs just to press the {character pullout} Key once.
On the other hand, when the user wants to input a certain English letter, he/she needs to repeatedly press the key that prints the intended letter for a specific number of times indicated by the order of that letter on the key. For instance, when the user wants to input the English letter "A", he/she needs to repeatedly press th {character pullout} key twice; when the user wants to input the English letter "E", he/she needs to repeatedly press the {character pullout} key for three times; and when the user wants to input the English letter "L", he/she needs to repeatedly press the {character pullout} for four times.
In addition to numbers and English letters, the CCITT-compliant keyboard 110 can also be used to input special symbols to the mobile-phone handset 100 that are customized by the manufacturer. For instance, when the user wants to input the symbol "&gt;", if provided, to the mobile-phone handset 100, he/she may need to press the {character pullout} jey repeatedly for 10 times. Inputting symbols to the mobile-phone handset 100 in such a manner may be highly laborious and time-consuming, but for a 12-key keyboard, it would usually be considered acceptable However, it nevertheless makes some advanced computer functions, such as networking and E-mail, very difficult to achieve. Moreover, using the 12-key CCITT-compliant keyboard 110 for Chinese input is even more laborious and time-consuming, so that running Chinese-based applications on the mobile-phone handset 100 is still quite difficult.
One solution to the foregoing problem is to couple the mobile-phone handset with a PDA (Personal Digital Assistant) or the like, whereby the task of Chinese-character input can be performed through the PDA. This is achieved by displaying a virtual keyboard on the LCD of the mobile-phone handset, and the virtual keyboard displays a set of phonetic symbols, such as those in the Mandarin Phonetic Symbol Set or the Roman Symbol Set to allow the user to perform the task of Chinese-character input through a pronunciation-based input scheme. A certain key on the virtual keyboard can be activated by touching that key with hand or pen.
One drawback to the foregoing solution, however, is that the displayed virtual keyboard on the LCD is quite small in size due to the LCD itself being very small in size, which makes the touching of each individual key on the virtual keyboard quite difficult to be targeted precisely. In consequence, wrong keys can often be mistakenly selected.
Moreover, since the above-mentioned virtual keyboard is activated by the coupled PDA and not by the CCITT-compliant keyboard on the mobile-phone handset, it would make the use of the mobile-phone handset more inconvenient.
To find solutions to the above-mentioned drawbacks of the prior art, it is still a research effort in the industry to develop an easy-to-use Chinese-character input method and system that allows the user to perform the task of Chinese-character input to the mobile-phone handset more conveniently and efficiently through the CCITT-compliant keyboard.